1. Field of the Invention
The present application relates to communication systems. Particularly, these embodiments are directed to allocating communication resources among the plurality of subscribers to a communication system.
2. Related Art
Several solutions have been presented to address the problem of allocating limited communication resources provided by a single node in a communication system among a plurality of subscribers. It is an objective of such systems to provide sufficient resources at the nodes to satisfy the requirements of all subscribers while minimizing costs. Accordingly, such systems are typically designed with the objective of efficient allocation of resources among the various subscribers.
Various systems have implemented a Frequency Division Multiple Access (FDMA) scheme, which allocates resources to each of the subscribers concurrently. A communication node in such systems typically has a limited bandwidth for either transmitting information to or receiving information from each subscriber in the network at any point in time. This scheme typically involves allocating distinct portions of the total bandwidth to the individual subscribers. While such a scheme may be effective for systems in which subscribers require uninterrupted communication with the communication node, better utilization of the total bandwidth may be achieved when such constant, uninterrupted communication is not required.
Other schemes for allocating communication resources of a single communication node among a plurality of subscribers include Time Division Multiple Access (TDMA) schemes. These TDMA schemes are particularly effective in allocating the limited bandwidth resources of a single communication node among a plurality of subscribers, wherein users do not require constant, uninterrupted communication with the single communication node. TDMA schemes typically dedicate the entire bandwidth of the single communication node to each of the subscribers at designated time intervals. In a wireless communication system which employs a Code Division-Multiple Access (CDMA) scheme, this may be accomplished by assigning to each of the subscriber units all code channels at the designated time intervals on a time multiplexed basis. The communication node implements the unique carrier frequency or channel code associated with the subscriber to enable exclusive communication with the subscriber. TDMA schemes may also be implemented in land line systems using physical contact relay switching or packet switching.
TDMA systems typically allocate equal time intervals to each subscriber in a round robin fashion. This may result in under utilization of certain time intervals by certain subscribers. Similarly, other subscribers may have communication resource requirements, which exceed the allocated time interval, leaving these subscribers under served. The system operator may choose to either incur the cost of increasing the bandwidth of the node to ensure that no subscribers are under-served, or allow under-served subscribers to continue to be under-served.
Accordingly, there is a need to provide a system and method of allocating communication resources among subscribers to a communication network efficiently and fairly according to a network policy of allocating the communication resources among the subscribers. Consistent therewith, there is a need to maximize the number of users served by the system, including, but not limited to, providing mechanisms for performing resource allocation on a per flow basis and/or on an aggregate basis in response to the specific requirements, constraints, and/or goals of the system. Still further there is a need for admission control and preemption methods which optimize resource allocation.